Surf the web long enough in search of information about gastrointestinal problems, and you’ll likely come across plenty of information about leaky gut syndrome in people. But can the same thing happen to your dog? Read on to find out.

What is “leaky gut”?

Leaky gut syndrome describes the condition that occurs when the connections between the cells of the intestinal lining — known as “tight junctions” — become loose, allowing intestinal contents to more easily pass between them.

Understanding leaky gut syndrome requires thinking for a minute about how we classify the inside of the gastrointestinal tract with relation to the rest of the body. Technically, everything from the mouth to the anus is inside the body, and the contents, which include food, intestinal bacteria and fecal material, are “dirty.” The body has ways of cleaning up intestinal contents before putting them into circulation to be utilized by the organs and tissues, most notably the detoxification processes that are completed in the liver. But of course, if substances leak across the intestinal lining, that cleanup process never occurs.

So how does the gut get leaky?

There are lots of theories about how these important cell-to-cell connections become disrupted, but no one is completely sure of all of the possible mechanisms. In cases of Crohn’s disease and celiac disease in people, it’s thought that some genetic abnormality is at the root of the leaky cells. Certain drug therapies and an imbalance of the normal gastrointestinal flora, aka good bacteria, of the gut may also play a role.

As leaky gut syndrome gets more airtime in the world of human disease, veterinary researchers and specialists are beginning to consider what role this condition may play in the diseases we see in dogs.

The gluten connection

People with celiac disease cannot digest gluten, a protein found in wheat that subsequently shows up in bread, pasta, crackers — any food that contains flour, and potentially any food produced in a facility that processes those types of foods. Dogs can have their own type of celiac disease, known as gluten-sensitive enteropathy. This condition can be inherited in Irish setters; otherwise, it’s not thought to be widespread in the canine population.

Many people report that they seem to feel better and experience resolution of chronic GI problems like diarrhea, bloating and abdominal pain when they eliminate gluten from their diet. The vast majority of these people do not have celiac disease, but many researchers believe that wheat may play a role in increasing the permeability or leakiness of the gut and contribute to these symptoms.

Is autoimmune disease caused by having a leaky gut?

Autoimmune disease in animals is on the rise, just like it is in people. Problems like hypothyroidism and diabetes in dogs are thought to be caused by the body’s immune system attacking its own normal tissue as if it were a foreign invader.

Having a leaky gut has been considered as a possible contributing factor to the development of autoimmune diseases in people. The theory is that when foreign proteins are able to cross into circulation, the body mounts an immune response against them, which may make the immune system more reactive in general and kickoff autoimmune disease.

It’s certainly a big leap to take to get from eating grains to increased risk of autoimmune disease, but many researchers believe that diet likely plays an important role in these conditions, so it’s likely that more research will focus on this connection in the future.

Food allergies may cause leaky gut

We’ve long suspected a connection between certain foods — typically proteins like chicken and beef, but also grains like corn and wheat — and allergic skin disease in dogs. Often dogs with itchy skin and chronic ear infections can get relief from changing to a hypoallergenic diet. Leaky gut syndrome may explain how the food that’s going through the GI tract can cause problems on the surface of the skin.

Many dog foods claim the titles “hypoallergenic” and “limited-ingredient,” but it’s important to understand that most of the foods that you can buy without a veterinarian’s prescription are manufactured in facilities not dedicated to production of that food. The result is that extremely sensitive individuals may still be affected by minute amounts of allergens in these foods.

Severe gastrointestinal injury can play a role

If you’ve read this far, you may be imagining gallons of foreign substances pouring into your dog’s body like water filtering out of a colander full of hot spaghetti. But we’re actually just talking about microscopic amounts — and really, that’s all it takes to potentially wreak havoc.

We’ve long suspected that puppies and dogs infected with the severe gastrointestinal virus known as parvovirus can become septicemic — meaning they have a bacterial infection in their blood — because of the gut becoming leaky due to the infection. Septicemia is an extremely serious and potentially life-threatening condition that can lead to a complete collapse of the circulatory system. Similar conditions occur in the gut when a dog experiences heatstroke.

How can I make sure my dog doesn’t get leaky gut syndrome?

Unfortunately, no one can answer this question because as I said in the beginning, no one is completely sure what causes it except in cases of parvo or heatstroke. Dogs may benefit from probiotic therapies developed specifically for the canine microbiome — that’s the specific array of good bacteria that live in the guts of dogs — as a way to ensure that the flora remain healthy and balanced. Also, you can work with your veterinarian to avoid the unjustified use of antibiotics, since it’s highly likely that they can disrupt the gut flora.

Does your dog need to eat a gluten-free or grain-free diet? Chances are good that he’s handling both just fine. However, if he’s having chronic skin or GI problems, it’s definitely worth investigating whether he might benefit from a hypoallergenic diet.